HP 3000 Manuals HP 3000 Manuals
Organization of the POSIX/iX Library
The POSIX/iX library consists of three relocatable library files:
* The file /lib/libc.a is a relocatable library file that includes C
library functions defined by ANSI C, the POSIX.1 standard, and
IEEE P1003.2/D11.2.
* The file /lib/libm.a is a relocatable library file containing all
ANSI C math library functions.
* The file /lib/libM.a is a relocatable library file containing all
common usage math library functions.
The POSIX/iX library
The POSIX/iX library file, /lib/libc.a, contains four classes of C
library functions:
* functions defined by ANSI C
* functions defined by the POSIX.1 standard
* functions defined by IEEE P1003.2/D11.2
* functions provided to increase portability between MPE/iX and
HP-UX
The POSIX/iX math library
The POSIX/iX math library consists of additional mathematical functions,
such as trigonometric and logarithmic functions, that perform
floating-point operations. These math library functions perform in a
manner defined by ANSI C.
NOTE It is recommended that you use the POSIX/iX math library when
developing applications using the MPE/iX Developer's Kit.
The common usage math library
The common usage math library consists of the same library functions
available in the POSIX/iX math library; however, common usage math
library functions perform in a pre-ANSI manner that does not conform to
either ANSI C or the POSIX.1 standard.
The primary difference between the two math libraries is the manner in
which errors are handled, such as attempting to compute the square root
of a negative value. POSIX/iX math library behavior causes the library
to call a user-written function named _matherr if one is provided, and no
error message is displayed. Common usage math library behavior causes
the library to call a user-written function named matherr if one is
provided; otherwise, an error message is displayed.